Your brain finds your mother’s voice very rewarding… until you turn 13.
Researchers from Stanford University say teenagers’ brains have a similar response to “nonfamilial” or newer voices, giving us a scientific explanation for that rebellious phase.
The study in The Journal of Neuroscience suggests a mother’s voice uniquely lights up multiple parts of a child’s brain.
After the age of 13 neuroanatomical changes stop this phenomenon and children respond in a similar way to newer voices too, particularly those outside the family.
“As a teen, you don’t know you’re doing this,” said lead author Daniel Abrams, PhD, clinical associate professor of psychiatry and behavioural sciences.
“You’re just being you: You’ve got your friends and new companions and you want to spend time with them. Your mind is increasingly sensitive to and attracted to these unfamiliar voices.”
The Stanford experts enrolled volunteers aged 7 to 16 for their study, all currently raised by their biological mothers, to study brain activity.
They used functional MRI or fMRI which can track neural activity and blood flow in the brain.
Recordings of gibberish words in different voices lasting just under a second were played to the volunteers as the researchers observed their brains.
In their previous study with children between the ages of 7 and 12, brains are tuned in to their mother’s voice, with infants, toddlers and pre-adolescents being able to identify their mothers’ voices with extreme accuracy.
Their mother’s voice can lead to certain brain regions associated with reward, emotion-processing and information-prioritisation getting activated.
The new study builds on the previous one, finding the phenomenon does not occur in the brain once the child reaches 13, instead the brain shifts towards finding unfamiliar voices rewarding.
“The voices in our environment are this incredibly rewarding sound source that allow us to feel connected, included, part of a community and part of a family,” Abrams said.
“Voices are really what connect us.”
So turns out when you tell your teenager to clean their room, it’s not simply because they don’t want to, their brains are no longer registering your voice in the same way as when they were younger.